Abstract

The nature of the inhomogeneous broadening of optical and ODMRspectral lines of aromatic molecules hosted in low temperature glasses is experimentally and theoretically investigated. Particular attention is paid to the relationships which exist between the various classes of inhomogeneously broadened spectral lines, and the salient features are illustrated with the results of ‘‘site selection’’ spectroscopy. A theoretical formalism based on the assumption of a uniform ‘‘solvent field’’ is presented and used to account for the major experimental features. Various ODMR line broadening mechanisms are considered and their relative importance evaluated.